President Donald Trump suggested Monday that "rogue killers" could be responsible for the mysterious disappearance of Saudi journalist Jamal Khashoggi, an explanation offering U.S. ally Saudi Arabia a possible path out of a global diplomatic firestorm. The Saudis continued to deny they killed the writer, but there were indications the story could soon change.

While Trump commented at the White House, Turkish crime scene investigators finally entered the Saudi consulate to comb the building where Khashoggi was last seen alive two weeks ago.

Trump spoke after a personal 20-minute phone call with Saudi King Salman and as the president dispatched his secretary of state to Riyadh for a face-to-face discussion with the king. Late in the day, there were published reports that the Saudis were preparing to concede that Khashoggi, a U.S.-based Saudi contributor to The Washington Post, had been killed in an interrogation gone wrong.

Before Monday Trump had focused less on possible explanations for Khashoggi's likely demise than on possible punishment if the Saudis were found culpable.

"The king firmly denied any knowledge of it," Trump told reporters as he left the White House for a trip to survey hurricane damage in Florida and Georgia. Trump said he didn't "want to get into (Salman's) mind," but he added, "it sounded to me like maybe these could have been rogue killers. I mean, who knows? We're going to try getting to the bottom of it very soon, but his was a flat denial."

Khashoggi, a critic of the Saudi government and in particular Crown Prince Mohammed bin Salman, was last seen entering the consulate on October 2 to get paperwork for his upcoming marriage to a Turkish woman. Turkish officials have said he was killed and dismembered.

In a sign of new cooperation between Turkey and Saudi Arabia that could shed light on the disappearance, Turkish investigators wearing coveralls and gloves entered the consulate Monday. It remained unclear what evidence they might be able to uncover. Earlier Monday, a cleaning crew with mops, trash bags and what appeared to be bottles of bleach walked in past waiting journalists.

Trump administration officials told The Associated Press that intelligence collected by the U.S. is inconclusive as to what actually happened to Khashoggi. With such a lack of clarity, the administration has not ruled out any possible scenario. The officials were not authorized to comment publicly on the matter and requested anonymity.

Secretary of State Mike Pompeo, hurriedly sent to Riyadh, expected to get more clarity during talks with Saudi leaders Tuesday. The White House expects credible answers quickly after Pompeo wraps up his trip with a stop in Ankara for meetings with senior Turkish officials.

The State Department has urged a thorough investigation into Khashoggi's disappearance and called on Saudi Arabia to be transparent about the results — advice broadly tracking messages from allies in Europe. Germany, Britain and France issued a joint statement over the weekend expressing "grave concern" and calling for a credible investigation to ensure those responsible for the disappearance "are held to account."

Trump quoted the King on Monday as saying that neither he nor his son, Crown Prince Mohammed, had any information about what had happened to Khashoggi.

The prince, ambitious, aggressive and just 33 in a kingdom long ruled by aging monarchs, has considerable weight in Saudi government actions. He and Trump's son-in-law and senior adviser, Jared Kushner, have forged close ties.

Just last week, Trump vowed to uncover the truth about what happened to Khashoggi and promised "severe punishment" for those responsible. But he has said repeatedly that he does not want to halt a proposed $110 billion arms sale to Saudi Arabia — as some in Congress have said he should — because it would harm the U.S. economically.

Saudi Arabia has pledged to retaliate economically for any U.S. punitive action. That would be an unprecedented breach in a decades-old, deep economic and security relationship that is key to Washington's policies in the Middle East. A Saudi-owned satellite channel later suggested the world's largest oil exporter could wield that production as a weapon against America.

White House economic adviser Larry Kudlow said Treasury Secretary Steven Mnuchin still plans to attend a previously scheduled Saudi conference this week to address terrorist financing, but those plans could change as the investigation progresses.

CNN reported that the Saudis were going to admit the killing had occurred but deny the king or crown prince had ordered it. The New York Times reported that the Saudi royal court would soon put out a narrative that an official within the kingdom's intelligence services — who happened to be a friend of Prince Mohammed — had carried out the killing. According to that narrative, the crown prince had approved an interrogation or rendition of Khashoggi back to Saudi Arabia, but the intelligence official was tragically incompetent as he eagerly sought to prove himself. Both reports cited anonymous people said to be familiar with the Saudi plans.

Trump said he could not confirm such reports. "I've heard that report but nobody's knows if it's an official report. So far it's just the rumor, the rumor of a report coming out," he said.

Turkey has wanted to search the consulate for days. Permission apparently came after a late Sunday night call between King Salman and Turkish President Recep Tayyip Erdogan. In statements after the call, both praised the creation of a joint Saudi-Turkish probe.

The Turkish inspection team included a prosecutor, a deputy prosecutor, anti-terror police and forensic experts, the state-run Anadolu news agency reported. Certain areas of the consulate were to remain off-limits, although officials would be able to inspect surveillance cameras, Turkish media reported.

The furor over Khashoggi has dealt a serious setback to Prince Mohammed's aggressive pitch for the kingdom as a destination for foreign investment. Several business leaders and media outlets have backed out of the upcoming investment conference in Riyadh, called the Future Investment Initiative.

They include the CEO of Uber, a company in which Saudi Arabia has invested billions of dollars; billionaire Richard Branson; JPMorgan Chase & Co. Chief Executive Jamie Dimon and Ford Motor Co. Executive Chairman Bill Ford.